One of the goals of a spinal fusion procedure is to unite two or more vertebrae to prevent them from moving independently of each other. This may be done to improve posture, increase ability to ventilate the lungs, prevent pain, or treat spinal instability and reduce the risk of nerve damage. According to the American Academy of Orthopedic Surgeons, approximately a quarter-million spinal fusions are performed each year, half on the upper and half on the lower spine.
Posterior spinal fusion surgery involves approaching the patient from the back of patient, as opposed to anterior or lateral spinal fusion through the abdomen or side. There are three know posterior fusion techniques (all three are typically performed with pedicle screw fixation). There have been various approaches and systems for performing posterior spinal surgery. Some conventional systems further include titanium construction that is compatible with current CT and MRI scanning technology, low profile implant systems, top-loading and top-tightening systems, and other parameters. Some systems also include cross-connectors that allow one-piece implant to be applied to a dual-rod construct for a top-loading approach.
Conventional devices and systems for linking rods have a number of disadvantages. Many cross-connectors do not provide sufficient flexibility when adjusting the devices either prior to, during, or after their placement into the patient. Alternatively, many cross-connectors have grown too complex with multiple parts, joints, and locking set screws. Thus, these devices force a surgeon to utilize a specific configuration, leaving very little room for adjustment in accordance with patient's physiological characteristics and needs. Further, these devices do not allow a surgeon to connect multiple rods by actuating a single setscrew mechanism.